Self-assembled monolayers (SAMs) are an excellent platform to implement and develop interfacial reactions for the preparation of versatile materials of pivotal importance for the fabrication of, among others, biochips, sensors, catalysts, smart surfaces and electronic devices. The development of methods for selective, efficient, simple and rapid surface transformations with control over the surface composition is still a fundamental challenge in surface science. The research described in this book is aimed at the fabrication and investigation of functional and reactive SAM-based platforms for the development of bioactive monolayers and surface chemical gradients.